Various forms of anti-swaying attachments for trailers have been heretofore designed, but none having high sway resistance ability have been provided for ready mounting on towing vehicles and trailers removably coupled together by conventional ball-and-socket type tow hitches with the anti-sway attachments requiring only slight modifications of the towing vehicle and no modifications of the associated trailer other than to removably clamp a portion of the anti-swaying attachment thereto.
Examples of previously patented anti-swaying attachments are disclosed in U.S. Pat. Nos. 2,685,545, 2,768,837, 3,297,340, 3,393,923, 3,400,948, 3,519,287 and 3,801,133.